JPH087262A - recoding media - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a recording medium having good abrasion resistance by a head and good adhesion of a printing layer. [Structure] On the substrate 12, a thermal recording layer 20 and a protective layer 2 are provided.
4, a printing layer 26 is provided. The protective layer 24 contains an ultraviolet curable resin and a block polymer having a silicon-containing polymer portion. Alternatively, it includes a UV-curable resin, a block polymer having a silicon-containing polymer portion, and a block polymer having a carboxyl group-containing polymer portion or a block polymer having an epoxy-containing polymer portion. When the protective layer 24 contains these block polymers, a recording medium satisfying both the abrasion resistance by the head and the adhesiveness of the printing layer can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium, and more particularly, to improving the appearance by printing and abrasion resistance and a printing layer by a magnetic head, a thermal recording head or the like or a guide contacting when a card is conveyed. And a recording medium capable of performing excellent recording.

[0002]

2. Description of the Related Art In various cards such as ID cards and prepaid cards, heat-sensitive recording is performed for displaying balance and the like in addition to magnetic recording. Thermal recording is widely used because it does not require development, has a high color density, and is inexpensive. In such a thermal recording type card,
For example, a heat-sensitive recording layer is provided on one surface of a base material, and the heat-sensitive recording layer is colored by heating with a thermal head or the like to display desired characters and the like.

In order to protect the surface of such a heat-sensitive recording layer and provide it with chemical resistance, a protective layer is usually provided. Further, since the components contained in the protective layer may cause the thermal recording layer to develop color, an intermediate layer is provided between the thermal recording layer and the protective layer in order to prevent this. The fogging phenomenon can be prevented by this intermediate layer.

However, since the intermediate layer and the protective layer are conventionally formed by offset printing, it is necessary to use an ink having offset printing suitability, such as solvents, reactive diluents, various additives and pigments. There were restrictions on the addition. Therefore, there is a restriction on the coating material that can be used for the protective layer, and an effective protective layer cannot be formed.

Further, since the intermediate layer and the protective layer are formed by offset printing, it is necessary to contain wax, an unreactive resin component or the like in order to have printability, and when printing with a thermal head, heating is required. Since these components elute, the thermal head becomes dirty and causes the print surface to be scratched.

Further, since the intermediate layer and the protective layer are formed by offset printing, pinholes are apt to be generated in these layers, and therefore, the heat-sensitive recording layer may be colored or erased by chemicals penetrating through the pinholes. was there.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the applicant of the present invention has applied a material containing an ultraviolet curable resin to the intermediate layer and the protective layer according to Japanese Patent Application No. 5-121880, and irradiates with the ultraviolet rays. Then, this was cured, and a thermal recording medium excellent in durability, abrasion resistance, heat resistance and chemical resistance, and a method for producing the same were proposed.

By the way, it is desired to provide a printing layer in order to improve the appearance of such a heat-sensitive recording medium and to give visible information fixed in advance.

However, the above-mentioned Japanese Patent Application No. 5-1218.
When the printing layer is formed on the protective layer after providing the protective layer according to No. 80, in order to prevent the hands and dirt from adhering to the surface of the card, silicone oil or silicone should be added to the paint forming the protective layer. Since a resin or the like is added, there is a problem in that even if a print layer is formed on a protective layer cured by ultraviolet irradiation, the adhesion is poor and the print layer is peeled off by rubbing with a weak force. In particular, the adhesion was poor in the case of black (smudge) printing.

On the other hand, if the amount of silicone oil is reduced, the adhesion of the printing layer will be improved, but the slipperiness will be insufficient and the abrasion resistance and scratch resistance will not be satisfied. Furthermore, since the silicone oil for imparting the slipperiness is easily released by breezing on the surface, the slipperiness cannot be maintained for a long period of time.

The present invention solves the above problems,
It is an object of the present invention to provide a recording medium which has a printed layer to improve its appearance and which is excellent in scratch resistance, abrasion resistance, heat resistance, chemical resistance and adhesiveness of the printed layer.

[0012]

According to the present invention, a recording having at least a recording layer, a protective layer containing an ultraviolet-curable resin provided on the recording layer, and a printing layer provided on the protective layer. In the medium, the protective layer contains a block polymer having a silicon-containing polymer portion.

According to the present invention, the protective layer further comprises a block polymer having a carbonyl group-containing polymer portion.

According to the present invention, the protective layer further comprises a block polymer having an epoxy group-containing polymer portion.

Further, according to the present invention, the recording medium is repeatedly worn by the contacting head.

[0016]

Embodiments of the recording medium according to the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment in which the present invention is applied to a thermosensitive magnetic recording medium. This thermosensitive magnetic recording medium
As shown in FIG. 1, a magnetic recording layer 14, a smooth layer 16, a reflective layer 18, a thermosensitive recording layer 20, an intermediate layer 22, a protective layer 24, a printing layer 26, and a printing protective layer 28 are sequentially laminated on a substrate 12. There is.

As the base material 12, for example, a synthetic resin sheet such as polyethylene terephthalate (PET), polyacetate, polystyrene (PS), epoxy resin, polyvinyl chloride (PVC) and polycarbonate (PC) or a synthetic paper is used. it can. The thickness of the base material 12 is usually about 100 to 300 μm.

The magnetic recording layer 14 may be the one generally used as a magnetic recording layer in this type of magnetic recording medium.

For example, as the magnetic material, Ba-ferrite having a particle size of 10 μm or less, preferably 0.01 to 5 μm, Sr
-Ferrite, Co coated γ-Fe ₂ O ₃ , γ-Fe ₂ O ₃ ,
Using needle-shaped iron powder and CrO ₂ , polyester resin, alkyd resin, which are generally used as binder resin,
A vinyl resin, a polyurethane resin, or a mixed resin thereof can be used.

The mixing ratio of the binder resin and the magnetic material is appropriately set in consideration of the adhesiveness with the substrate 12, the strength of the coating film, the voltage detected by the magnetic head, and the like. Usually, the weight ratio is in the range of former / latter = 1/1 to 1/10, preferably 1/2 to
1/8 is appropriate.

The thickness of the magnetic recording layer 14 is usually 5 to 20.
It is about μm.

The smooth layer 16 is a layer for flattening the unevenness of the magnetic recording layer 14 and improving the adhesion of the reflective layer 18, and is formed by gravure coating an ultraviolet curable resin. The thickness of the smooth layer 16 is, for example, 1
It is about 5 μm.

The reflective layer 18 has a color that visually hides the color of the magnetic recording layer 14 and imparts sufficient contrast to the color of the thermosensitive recording layer 20. Further, the properties that the material used to form the reflective layer 18 should have are stable under the heat-sensitive recording conditions and have sufficient durability even if thin, and the heat-sensitive recording layer 20 of the material forming the magnetic recording layer 14 is provided. It is possible to prevent the transition to.

As such a heat resistant material, thermosetting resin such as polyamide resin, epoxy resin, acrylic resin, phenol resin, unsaturated polyester resin, polyurethane resin, diallyl phthalate resin can be used. Pigment for concealing property such as Al, Sn,
Zn, Cu, Ag, Cu- Zn , etc. of the metal and Al ₂ 0 _3, T
and i0 ₂ a metal oxide such an appropriate amount.

As the reflective layer 18, in addition to the thermosetting resin as described above, a non-magnetic metal layer having a high reflectance such as Al or S is used.
It is also possible to use layers of n, Ag or oxides of these metals.

The thickness of the reflective layer 18 is, for example, 0.03 to 0.
It is about 1 μm.

As the material constituting the heat-sensitive recording layer 20,
A heat-sensitive recording material used for ordinary heat-sensitive recording performed by a thermal head or the like is used. Such a thermosensitive recording material is mainly composed of a polymer binder and a thermosensitive coloring material. As the polymer binder, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, starch, styrene-maleic acid copolymer, polymethylmethacrylate, homopolymer or copolymer of methacrylic resin such as polyethylmethacrylate, polystyrene, Acrylic-styrene copolymer, polyester resin, coumarone resin, ABS resin, nitrocellulose, etc. can be used.

The thermosensitive coloring material is a combination of a developer having a phenolic hydroxyl group and a colorless leuco dye, and 4,4'-isopropylidenephenol, benzyl-p-hydroxybenzoate, 4,
4′-dihydroxy-3,5′-diallyldiphenyl sulfone, methyl-bis (hydroxyphenyl) acetate, gallic acid ester, p-phenylphenol and the like can be mentioned. As leuco dyes, crystal violet lactone, 3-indolino-3-p-dimethylaminophenyl-6-dimethylaminophthalide, 3-diethylamino-7-chlorofluorane, 2- (2-chlorophenylamine) -diethylaminofluorane. , 2- (2-
Fluorophenylamino) -6-diethylaminofluorane, 2- (2-fluorophenylamino) -6-di-
n-Butylaminofluorane, 3-diethylamino-7
-Cyclohexylaminofluorane, 3-diethylamino-5-methyl-7-t-butylfluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3
-Diethylamino-6-methyl-7-p-butylanilinofluorane, 3-cyclohexylamino-6-chlorofluorane, 2-anilino-3-methyl-6- (N-ethyl-p-toluidino) -fluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 3-pyrrolidino-7-cyclohexylaminofluorane, 3-N-methylcyclohexylamino-6-methyl-7-anilinofluorane, 3-N-ethyl Mention may be made of pentylamino-6-methyl-7-anilinofluorane and the like.

The thermal recording layer 20 is formed to have a thickness of 3 to 5 μm.

The heat-sensitive recording layer 20 is preferably formed of a reversible heat-sensitive recording material rather than formed of the above-mentioned irreversible heat-sensitive recording material. The reversible thermosensitive recording material comprises a resin such as polyester and an organic low-molecular substance dispersed in the resin, as described in JP-A-57-109695 and JP-A-2-187389. ing. In the reversible thermosensitive recording material, the transparency changes because the refractive index of the organic low molecular weight substance becomes equal to or different from that of the resin by selecting the heating temperature. That is, as shown in FIG.
If it is below 0 and it is cloudy, the temperature T1
After heating to ~ T2, cool to below T0 (arrow A)
Then, the refractive index of the organic low molecular weight substance becomes substantially equal to that of the resin, so that the reversible thermosensitive recording layer changes to a transparent state.

Furthermore, when this is heated to a temperature of T3 or higher and then cooled to a temperature of T0 or lower (arrow B), since the refractive index of the organic low molecular weight substance is different from the refractive index of the resin, light scattering occurs and reversible heat sensitivity is obtained. The recording layer changes to a cloudy state again.

Further, the reversible thermosensitive recording layer is formed at temperatures T0 to T.
When heated to 1 or T2 to T3 and then cooled to a temperature of T0 or lower (arrow C or D), the reversible thermosensitive recording layer is in a state between transparent and cloudy.

The reversible thermosensitive recording material can repeat such a state change.

To give an example of the above T0 to T3, they are 60 ° C., 70 ° C., 80 ° C. and 110 ° C., respectively.

As the resin used in the reversible thermosensitive recording material, those having high transparency, excellent mechanical strength and good film forming property are preferable. Specific examples thereof include polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer, vinyl chloride-acrylate copolymer. , Polyvinylidene chloride, vinylidene chloride-
Examples thereof include vinyl chloride copolymers, vinylidene chloride-acrylonitrile copolymers, polyester resins, polyamide resins, acrylic resins and silicone resins. Of these, particularly preferred are vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer,
Vinyl chloride-vinyl acetate-vinyl alcohol copolymer,
Polyester resin is applicable.

As the organic low molecular weight substance, alkanol,
Alkane diol, halogen alkanol or halogen alkane diol, alkylamine, alkane, alkene, alkyne, halogen alkane, halogen alkene, halogen alkyne, cycloalkane, cycloalkene, cycloalkyne, saturated or unsaturated mono- or dicarboxylic acid or ester thereof, Amides, or ammonium salts, saturated or unsaturated halogen fatty acids or their esters, amides, or ammonium salts, acrylic carboxylic acids or their esters, amides, or ammonium salts, halogen acrylic carboxylic acids or their esters, amides, or ammonium Salts, thioalcohols, thiocarboxylic acids or their esters, amides, or ammonium salts, carboxylic acid esters of thioalcohols. In, and the number of carbon atoms from 10 to 40,
The molecular weight may be 100 to 700. Particularly preferred are higher fatty acids such as lauric acid, valmitic acid, stearic acid, arachidic acid and behenic acid having a melting point in the range of 50 to 150 ° C., or their esters, amides or ammonium salts, or aliphatic dicarboxylic acids. It is a combination of an acid and a higher fatty acid ester.

The mixing ratio of the resin and the organic low molecular weight substance is as follows:
5 parts by weight of organic low molecular weight substance to 100 parts by weight of resin
The range of 200 parts is preferable, and 10 to 100 parts are preferable.
Parts are more preferred.

The thickness of the intermediate layer 22 is, for example, 0.5-1.
It is about μm. The thickness of the protective layer 24 is 1 to 5 μm.
m, preferably about 1 to 3 μm.

The intermediate layer 22 is a layer for preventing the heat-sensitive recording layer 20 from being colored by the organic solvent contained in the coating material of the protective layer 24 when the protective layer 24 is provided. That is, when the protective layer 24 is directly provided on the irreversible heat-sensitive recording layer 20 as described above, the heat-sensitive recording layer 20 is colored by the organic solvent contained in the protective layer 24, and recording by heat cannot be performed. The intermediate layer 22 is provided to prevent this.

The intermediate layer 22 is made of a thermoplastic resin, a two-component curing type resin, an oxidative polymerization type resin, an ultraviolet curing type resin or the like, and is formed by coating.

When a solvent is required for the paint used for the intermediate layer 22, the solvent must be one that does not attack the heat-sensitive recording layer 20, and water or an aromatic hydrocarbon such as toluene or xylene, Alcohols such as methanol, ethanol and isopropanol, cycloalkanes such as cyclohexane, aliphatic hydrocarbons such as n-hexane,
Other hydrocarbon-based solvents with relatively weak polarity are used.

As a coating means, a coating such as a roll coater, a gravure coater, a bar coater or a knife coater is used.

When the intermediate layer 22 is made of a water-soluble resin, for example, the water-soluble protective layer cannot be used, and the water-soluble resin coating material swells due to the organic solvent contained in the protective layer. In addition, some of them have solubility in alcohol, and thus have a difficulty in chemical resistance. Further, when the intermediate layer 22 is formed by offset printing, a large number of pinholes are generated, and the protective layer 24 passes through the pinholes. May penetrate into the heat-sensitive recording layer 20 to form a color, but when the intermediate layer 22 is formed by coating with an ultraviolet curable resin, the intermediate layer 22 has excellent chemical resistance, and pinholes do not occur. It is preferable because the thermal recording layer 20 is not colored or decolored by permeation of the solvent of 24.

In particular, since the heat-sensitive recording layer composed of the leuco dye and the color developer is formed of a dispersed material, it is generally porous as compared with the reversible heat-sensitive recording layer described above, and has many irregularities on the surface. is there. When the intermediate layer 22 is formed by offset printing, since the viscosity of the coating material is high, the coating material does not enter the irregularities on the surface of the thermal recording layer 20, and the irregularities on the surface of the thermal recording layer 20 cannot be flattened. However, when the intermediate layer 22 is formed by coating with an ultraviolet curable resin, the viscosity of the coating material of the intermediate layer 22 may be very low, so that it cures in a state where it enters into the irregularities on the surface of the heat-sensitive recording layer 20, The unevenness of the surface of the recording layer 20 can be made flat, and since the ultraviolet curable resin is resistant to an organic solvent after curing, a thermosensitive recording medium excellent in chemical resistance can be obtained, which is preferable.

The intermediate layer 22 is not essential to the present invention and may be omitted.

The protective layer 24 is provided to improve the scratch resistance and chemical resistance of the surface of the heat-sensitive recording layer 20 and to improve the wear resistance due to friction of the heat-sensitive head and the adhesion of the printing layer 26. . The protective layer 24 contains an ultraviolet curable resin and a block polymer having a silicon-containing polymer portion. The protective layer 24 preferably contains a block polymer having a carboxyl group-containing polymer portion or a block polymer having an epoxy group-containing polymer portion together with an ultraviolet curable resin and a block polymer having a silicon-containing polymer portion. The preferable addition ratio of these will be described later.

When the intermediate layer 22 is formed by coating and the protective layer 24 is formed thereon by coating, most of solvents, reactive diluents, various additives and pigments can be used. , Paints for all protective layers can be used. Therefore, since the chemical resistance is improved, it is possible to prevent the background fog and the disappearance of the printing due to the alcohol, the plasticizer and the like.

The protective layer 24 is formed of a material containing an ultraviolet curable resin as described above and is cured by irradiation with ultraviolet rays.

Further, when the print layer 26 and the print protection layer 28 are formed by offset printing using a UV offset ink containing an ultraviolet curable resin, the print layer 26 is used.
After printing, the print protection layer 28 is printed, and the print layer 26 and the print protection layer 28 are cured by irradiating with ultraviolet rays. The print layer 26 and the print protection layer 28 may be formed using ink containing an oxidative polymerization type resin.

The print layer 26 is a layer on which visible information such as desired characters and patterns is formed by printing. The print layer 26 is formed so that the visible recording information recorded on the thermosensitive recording layer 20 can be seen.

Therefore, according to the thermosensitive magnetic recording medium of the present embodiment, since the protective layer 24 is formed by using the ultraviolet curable resin, the block polymer having the silicon-containing polymer portion is excellent in the scratch resistance and the chemical resistance. Since the polymer portion containing silicon appears on the surface of the protective layer 24, the thermal head and the magnetic head have good slidability. In addition, unlike the case where a thin film is formed on the surface of the protective layer 24 such as silicone oil or wax, the polymer portion containing silicon appears as floating islands on the surface of the protective layer, so that the adhesion with the printing layer 26 is improved. To do.

When the protective layer 24 contains a block polymer having a silicon-containing polymer portion, a block polymer having a carbonyl group-containing polymer portion, a block polymer having a carboxyl group-containing polymer portion, or a block polymer having an epoxy group-containing polymer portion. As shown in FIG. 6, the polymer portion containing silicon, ○,
Further, a polymer portion containing a carboxyl group or a polymer portion containing an epoxy group Δ is mixed at the molecular level to be oriented and appears on the surface of the protective layer 24 to form a floating island structure, and the other polymer portion □ is oriented in the protective layer 24. Therefore, the polymer portion ○ containing silicon appearing on the surface of the protective layer 24 contributes to the improvement of the slipperiness of the head (the range shown by the solid line), and the polymer portion containing a carboxyl group or the polymer portion Δ containing an epoxy group is printed layer 26. Contributes to the improvement of the adhesiveness (in the range shown by the dotted line) of the head, and the adhesiveness of the print layer 26 is further improved. It is tightly bound and is not easily removed by a solvent or the like, and deterioration of the slipperiness of the head and the adhesion of the printing layer 26 is extremely small.

FIG. 2 shows another embodiment of the recording medium according to the present invention. In this embodiment, the print layer 30 and the print protection layer 32 are sequentially laminated on one surface of the substrate 12, and the magnetic recording layer 14, the smoothing layer 16, the reflective layer 18, and the heat-sensitive recording layer are formed on the other surface. 20, protective layer 24, printing layer 26,
The print protection layer 28 is sequentially stacked.

The substrate 12, the magnetic recording layer 14, the smoothing layer 16,
Reflective layer 18, thermosensitive recording layer 20, protective layer 24, printed layer 2
6. The print protection layer 28 is formed as in the embodiment of FIG.

FIG. 3 shows another embodiment of the recording medium according to the present invention. In this embodiment, the thermosensitive recording layer 20, the protective layer 24, the printing layer 26, and the printing protective layer 28 are sequentially laminated on the substrate 12.

The substrate 12, the thermosensitive recording layer 20, the protective layer 24,
The print layer 26 and the print protection layer 28 are formed similarly to the embodiment of FIG.

FIG. 4 shows another embodiment of the recording medium according to the present invention. In this embodiment, the magnetic recording layer 14, the protective layer 24, the printing layer 26, and the printing protective layer 28 are sequentially laminated on the substrate 12.

The substrate 12, the magnetic recording layer 14, the protective layer 24,
The print layer 26 and the print protection layer 28 are formed similarly to the embodiment of FIG.

The recording medium according to the present invention is not limited to the above embodiment, and for example, the magnetic recording layers 14 and
Smoothing layer 16, reflective layer 18, thermosensitive recording layer 20, protective layer 2
4, the print layer 26, and the print protection layer 28 may be provided. Further, in the case of FIGS. 2 and 3, an intermediate layer 22 may be provided between the thermal recording layer 20 and the protective layer 24.

The heat-sensitive recording medium according to the present invention is applicable not only to cards but to various recording media.

Next, specific examples of the recording medium according to the present invention will be described with respect to the composition and physical property evaluation of the protective layer 24 in comparison with comparative examples.

(Example 1) A protective layer 24 was formed of the following materials in the respective compositions shown in Table 1, and the following tests were conducted.
The results shown in Table 1 were obtained. The numbers in Table 1 are expressed in parts by weight as solids.

・ UV curable resin C3-374, manufactured by Dainippon Ink and Chemicals, Inc. ・ Block polymer having a carboxyl group-containing polymer portion H500, manufactured by NOF Corporation ・ Block polymer having a silicon-containing polymer portion FS
710 Nippon Oil & Fats Co., Ltd. ・ Diluent Isopropyl alcohol

Table 1 Test results Example UV carboxyl group Silicon-containing diluting liquid Printing head number Curing type-containing polymer Polymer isop Adhesive slippery resin Ropile block block with part having polymer part Alcopolymer polymer polymer C3-374 H500 FS710 ( Solid content 75%) (Solid content 30%) (Solid content 15%) 1 (1) 75 0 0 50 Good Not good 1 (2) 75 0 0.015 50 Good Good 1 (3) 75 0 0.030 50 Good Yes 1 (4 ) 75 0 0.075 50 No Good 1 (5) 75 0.15 0.075 50 Yes Good 1 (6) 75 0.30 0.075 50 Good Good 1 (7) 75 0.75 0.075 50 Good Good 1 (8) 75 1.50 0.075 50 Good Good 1 (9 ) 75 3 0.075 50 Good Good 1 (10) 75 6 0.075 50 Good Good 1 (11) 75 3 0.15 50 Good Good 1 (12) 75 3 0.30 50 Good Good 1 (13) 75 3 0.75 50 Good Good 1 (14 ) 75 3 1.50 50 No Good

The coating composition for the protective layer having the above composition was applied with a # 4 wire bar and dried at 40 ° C. for 2 minutes, and then the dried medium was conveyed at 30 m / min, and a UV lamp (160 W / 160 W /
cm × 3 lamps) and irradiate it with ultraviolet light to cure it, and the thickness is about 2 μm.
The protective layer 24 of was formed.

The printed layer 26 formed on the protective layer 24 was subjected to an adhesion test of the printed layer by removing the cellophane tape. In the test results of Table 1, "good" means that they are completely adhered to each other, "good" means that they are partially peeled but practically usable, and "not good" means that they are completely peeled.

A magnetic head slidability test was carried out on the above-mentioned protective layer 24 by a rubbing test of 1,000 reciprocations with a magnetic head having a load of 500 g. In the test results of Table 1, "good" means that there is no scratch, "good" means that some scratches are seen but can be used practically, and "impossible" means that scratches occur 500 times or less and cannot be used practically.

As can be seen from the test results in Table 1, when both the block polymer having the carboxyl group-containing polymer portion and the block polymer having the silicon-containing polymer portion were added, Examples 1 (5) to 1 (13) were obtained. Up to practical use. Therefore, since the block polymer having the silicon-containing polymer portion is added in the range of 0.075 to 0.75 parts by weight with respect to 75 parts by weight of the ultraviolet curable resin, 1 part by weight of the ultraviolet curable resin is used. It is preferable that the amount is not less than / 1000 parts by weight and not more than 1/100 parts by weight. Further, since the block polymer having a carboxyl group-containing polymer portion is added in the range of 0.15 to 6 parts by weight, the block polymer 1 having a silicon-containing polymer portion 1
The amount is preferably 2 parts by weight or more and 80 parts by weight or less with respect to parts by weight.

In Examples 1 (5) to 1 (13), 1
Particularly preferred are (6) to 1 (9) and 1 (11). In this case, the block polymer having a silicon-containing polymer portion is 0.075 to 75 parts by weight of the ultraviolet curable resin.
Since it is added in the range of 0.15 parts by weight, it is 1/1000 parts by weight or more /
It is particularly preferable that the amount is 500 parts by weight or less. Further, since the block polymer having a carboxyl group-containing polymer portion is added in the range of 0.30 to 3 parts by weight, 4 parts by weight or more and 40 parts by weight or less relative to 1 part by weight of the block polymer having a silicon-containing polymer portion. Is particularly preferable.

When only the block polymer having the silicon-containing polymer portion was added, the results were obtained in Examples 1 (2) and 1
(3) is practical. Therefore, since the block polymer having the silicon-containing polymer portion is added in the range of 0.015 to 0.030 parts by weight with respect to 75 parts by weight of the ultraviolet curable resin, 1 part by weight of the ultraviolet curable resin is used. It is preferable that the amount is / 5000 parts by weight or more and 1/2500 parts by weight or less.

Example 2 A protective layer 24 was formed of the following materials in the respective compositions shown in Table 2, and the following tests were conducted.
The results shown in Table 2 were obtained. The numbers in the table are parts by weight as solids.

UV curable resin C3-374 manufactured by Dainippon Ink and Chemicals, Inc. Block polymer having epoxy group-containing polymer moiety
H600 manufactured by NOF CORPORATION ・ Block polymer FS with silicon-containing polymer
710 Nippon Oil & Fats Co., Ltd. ・ Diluent Isopropyl alcohol

Table 2 Test Results Example UV Epoxy Group Silicon-Containing Diluting Solution Printing Head No. Curing-Type Containing Polymer Polymer Isop Adhesive Sliding Resin Ropylic Block Block Alcopolymer Polymer Polymer C3-374 H600 FS710 (with a portion having a resin portion) Solid content 75%) (Solid content 25%) (Solid content 15%) 2 (5) 75 0.375 0.075 50 Good Good 2 (6) 75 1.25 0.075 50 Good Good 2 (7) 75 2.5 0.15 50 Good Good 2 (8 ) 75 2.5 0.75 50 Yes Good 2 (9) 75 2.5 1.50 50 No Good

The coating material for the protective layer having the above composition was applied with a # 4 wire bar and dried at 40 ° C. for 2 minutes, and then the dried medium was conveyed at 30 m / min while a UV lamp (160 W /
cm × 3 lamps) and irradiate it with ultraviolet light to cure it, and the thickness is about 2 μm.
The protective layer 24 of was formed.

The print layer 26 formed on the protective layer 24 was subjected to an adhesion test of the print layer 26 by peeling with cellophane tape. "Good" in the test results of Table 2
Indicates that they are completely adhered, “OK” means that they are partially peeled but can be used practically, and “I” is that they are completely peeled.

A magnetic head slidability test was performed on the above-mentioned protective layer 26 by a rubbing test of 1,000 reciprocations with a magnetic head having a load of 500 g. In the test results of Table 2, "good" means that there is no scratch, "good" means that some scratches are seen but can be used practically, and "impossible" means that scratches occur 500 times or less and cannot be used practically.

As can be seen from the test results in Table 2, when both the block polymer having the epoxy group-containing polymer portion and the block polymer having the silicon-containing polymer portion were added, Examples 2 (5) to 2 (8) were obtained. Up to practical use. Therefore, the block polymer having the silicon-containing polymer portion is 0.
Since it is added in the range of 075 to 0.75 parts by weight,
The amount is preferably 1/1000 parts by weight or more and 1/100 parts by weight or less with respect to 1 part by weight of the ultraviolet curable resin. Also,
Since the block polymer having the epoxy group-containing polymer portion is added in the range of 0.375 to 2.5 parts by weight, the block polymer having the silicon-containing polymer portion 1
The amount is preferably 5 parts by weight or more and 17 parts by weight or less with respect to parts by weight.

In Examples 2 (5) to 2 (9), 2
(5) to 2 (7) are particularly preferable. In this case, since the block polymer having the silicon-containing polymer portion is added in the range of 0.075 to 0.15 parts by weight to 75 parts by weight of the ultraviolet curing resin, 1 part by weight of the ultraviolet curing resin is added. On the other hand, it is particularly preferable that the amount is 1/1000 parts by weight or more and 1/500 parts by weight or less. Further, the block polymer having an epoxy group-containing polymer portion is 0.375 to 2.5.
Since it is added in the range of parts by weight, it is particularly preferable that the amount is 4 parts by weight or more and 17 parts by weight or less with respect to 1 part by weight of the block polymer having the silicon-containing polymer portion.

(Comparative Example) As a comparative example, the protective layer 24 was formed from the following materials with the respective compositions shown in Table 3, and the following tests were conducted. The results shown in Table 3 were obtained. The numbers in the table are parts by weight as solids.

・ Ultraviolet curable resin C3-374 manufactured by Dainippon Ink & Chemicals, Inc. ・ Block polymer having a carboxyl group-containing polymer portion H500 manufactured by NOF CORPORATION ・ Silicone oil SH28A manufactured by Toray Dow Corning Silicone ・ Diluent isopropyl alcohol

Table 3 Test Results Comparative Example UV Carboxyl Group Silicon Diluent Printing Head No. Curing Type Containing Polymer Oil Isop Adhesive Slippery Ropile Block Alcopolymer with a resin part C3-374 H500 SH28PA (solid content 75%) ( Solid content 30%) (Solid content 100%) (1) 75 0.3 0.075 50 No Good (2) 75 3.0 0.075 50 No Good

The coating composition for the protective layer having the above composition was applied with a # 4 wire bar and dried at 40 ° C. for 2 minutes, and then the medium after drying was conveyed at 30 m / min while UV lamp (160 W / 160 W /
cm × 3 lamps) and irradiate it with ultraviolet light to cure it, and the thickness is about 2 μm
The protective layer 24 of was formed.

The print layer 26 formed on the protective layer 24 was subjected to an adhesion test of the print layer 26 by peeling with a cellophane tape. In the test results of Table 3, in both (1) and (2), the printing layer was completely peeled off, and the adhesion was not practical.

A magnetic head slidability test was conducted on the above-mentioned protective layer 24 by a rubbing test of 1,000 reciprocations with a magnetic head having a load of 500 g. In the test results of Table 3, there were no scratches in both (1) and (2).

As can be seen from the test results in Table 3, Comparative Example
In both (1) and (2), the adhesiveness of the printing layer 26 was poor, and it could not be put to practical use.

(Comparison between Example and Comparative Example) Above Comparative Example
Regarding (1) (2) and the protective layers 24 of Examples 1 (6) and 1 (11) in Table 1, the protective layer 2 was made of a cloth impregnated with isopropyl alcohol.
A test was performed on the slipperiness of the magnetic head after rubbing the 4 surfaces 50 times. The results are shown in Table 4.

Table 4 Before rubbing After rubbing Head slipperiness Head slipperiness Example 1 (6) Good Good Example 1 (11) Good Good Comparative Example (1) Good Yes Example (2) Good Yes

As can be seen from Table 4, Example 1 (6), 1
In (11), the slidability of the magnetic head was not deteriorated even after rubbing, whereas in Comparative Examples (1) and (2), deterioration was observed. In Comparative Examples (1) and (2), Table 3
As shown in FIG.
6 was completely peeled off.

[0090]

According to the present invention, since the protective layer contains a block polymer having a silicon-containing polymer portion together with an ultraviolet curable resin, it is excellent in scratch resistance and chemical resistance, and the thermal head and magnetic head have good slipperiness. Unlike the case where a thin film is formed on the surface of the protective layer, such as silicone oil or wax, the adhesion of the printed layer on the protective layer is good, and the slipperiness of the head and the adhesiveness of the printed layer on the protective layer are good. Is very little deteriorated.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment in which the present invention is applied to a thermosensitive magnetic recording medium.

FIG. 2 is a cross-sectional view showing another embodiment in which the present invention is applied to a thermosensitive magnetic recording medium.

FIG. 3 is a sectional view showing an embodiment in which the present invention is applied to a thermal recording medium.

FIG. 4 is a sectional view showing an embodiment in which the present invention is applied to a magnetic recording medium.

FIG. 5 is a diagram showing a state change of a reversible thermosensitive recording material.

FIG. 6 is a view showing a structure of a polymer portion on the surface of a protective layer according to the present invention.

[Explanation of symbols]

 12 Base Material 14 Magnetic Recording Layer 16 Smoothing Layer 18 Reflective Layer 20 Thermal Recording Layer 22 Intermediate Layer 24 Protective Layer 26, 30 Printing Layer 28, 32 Printing Protective Layer

Claims (8)

[Claims] 1. A recording medium having at least a recording layer, a protective layer provided on the recording layer and containing an ultraviolet curable resin, and a print layer provided on the protective layer, wherein the protective layer is A recording medium comprising a block polymer having a silicon-containing polymer portion. 2. The recording medium according to claim 1, wherein the protective layer comprises one block polymer having the silicon-containing polymer portion with respect to 1 part by weight of the ultraviolet curable resin.
A recording medium characterized by being added in an amount of not less than 5,000 parts by weight and not more than 1/2500 parts by weight. 3. The recording medium according to claim 1, wherein the protective layer further contains a block polymer having a carboxyl group-containing polymer portion. 4. The recording medium according to claim 3, wherein the protective layer comprises one block polymer having the silicon-containing polymer portion with respect to 1 part by weight of the ultraviolet curable resin.
/ 1000 parts by weight or more and 1/100 parts by weight or less are added,
A recording medium comprising 2 to 80 parts by weight of the block polymer having the carboxyl group-containing polymer portion added to the block polymer having the silicon-containing polymer portion. 5. The recording medium according to claim 1, wherein the protective layer further contains a block polymer having an epoxy group-containing polymer portion. 6. The recording medium according to claim 5, wherein the protective layer comprises one block polymer having the silicon-containing polymer portion with respect to 1 part by weight of the ultraviolet curable resin.
/ 1000 parts by weight or more and 1/100 parts by weight or less are added,
A recording medium, characterized in that 5 parts by weight or more and 17 parts by weight or less of the block polymer having the epoxy group-containing polymer portion is added to the block polymer having the silicon-containing polymer portion. 7. The recording medium according to claim 1, wherein the recording medium is repeatedly worn by a head that contacts the recording medium. 8. The recording medium according to claim 1, wherein the recording layer includes a magnetic recording layer or a thermosensitive recording layer that develops color by heating.